---
layout: default
title: Stage 3
nav_order: 3
parent: Stages
permalink: docs/stages/stage-3
---

{% capture preface %}
> The purpose of this stage is to add a linear rail on the X axis. We'll basically be trading the weight from the original steel printhead carriage and its wheels for an MGN9 rail of similar weight. Thus, the benefits of this stage aren't as much weight removal as the ability to use a modern printhead such as the Ratrig EVA or the Vz Printhead, plus complete liberation from those frustrating v-slot wheels.
{: .fs-5 .fw-300 .text-grey-dk-100 .text-justify }
{% endcapture %}
{% include docs-preface.html
  title="# Stage 3: Linear X Rail"
  image="/assets/images/docs/stages/stage-3/stage-3-render-lg.png"
  content=preface
%}

---

## Bill Of Materials

#### Linear Rails

| Size             | Length | Quantity | Link                                                                                                                                                                                     |
| :--------------- | :----- | :------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| MGN9H Rail+Block | 400mm  | 1        | [Amazon](https://www.amazon.com/gp/product/B09XQ7YWPT), [Fabreeko](https://www.fabreeko.com/collections/honeybadger/products/honeybadger-mgn9h-black-steel-rails?variant=43180948685055) |

{: .note }
You actually only need a 350mm MGN9 rail, but if you want to upgrade to stage 4 (coming soon) in which we'll be dropping the entire 2020 extrusion on the gantry, you'll want 400mm. It's up to you.

#### Bolts

| Part             | Type              | Quantity | Link                                                   |
| :--------------- | :---------------- | :------- | :----------------------------------------------------- |
| M3x8 socket head | ISO 4762, DIN 912 | 8        | [Amazon](https://www.amazon.com/gp/product/B08R3GJGWT) |

#### T-Nuts

| Size           | Quantity | Link                                                   |
| :------------- | :------- | :----------------------------------------------------- |
| M3 2020 T-nuts | 8        | [Amazon](https://www.amazon.com/gp/product/B08NZMD2BJ) |

---

{% capture vz %}
**Usable Print Area:** 220 x 200 (20mm reduction on Y axis)

The Vz Printhead is an impressively simple printhead used on the blazing fast VzBot printer. It has all the features you'd expect from a modern printhead including many popular hotends, extruders, and Z probes (BLTouch and SuperPINDA). It also as well as some less-common features like adjustable-height fan ducts and CPAP cooling.

The only drawback with this printhead is that you may not already have the [30mm standoffs](https://speedyfpv.com/products/10pcs-m3x30mm-aluminum-spacer-standoff-silver-anodized?variant=37983057936557) on hand to complete the build (< $10 with shipping).

The official design only required three parts to be modified in order to work on the Endorphin. So start by downloading the official STLs from [here](https://github.com/VzBoT3D/Vz-Printhead-Printed/tree/main/STLs) and you can find the BOM [here](https://github.com/VzBoT3D/Vz-Printhead-Printed/tree/main/BOM). Then before you start printing parts, check the table below and substitute any of the original parts listed below with the Endorphin part:

| Original Part                   | Endorphin Part                                                             |
| :------------------------------ | :------------------------------------------------------------------------- |
| Back plate round standoff.stl   | [vz-back_plate.stl](/assets/stl/docs/stages/stage-3/vz-back_plate.stl)     |
| Bottom plate round standoff.stl | [vz-bottom_plate.stl](/assets/stl/docs/stages/stage-3/vz-bottom_plate.stl) |
| Front round standoff.stl        | [vz-front.stl](/assets/stl/docs/stages/stage-3/vz-front.stl)               |

{: .note }
Make sure you print the MGN9**H** version of the carriage top (assuming you bought your rails from the links above) rather than the MGN9**C** version.
{% endcapture %}
{% include docs-step.html
  heading="## Vz Printhead"
  image="/assets/images/docs/stages/stage-3/vz.png"
  content=vz
%}

### Belt Clips

Either of the following belt clips provided with the printhead will work fine so pick whichever one you prefer. The original Vz printhead has been modified so that the posts sit at the right height for the Endorphin belts. Just remember that you only need to print off clips for 2 belt ends rather than the 4 needed in a CoreXY, which means you can choose whether you want to attach the belt ends on the front or rear posts (just don't do one front and one rear). The other side will be unused.
{: .mb-8 }

{% capture belts1 %}
This clip is incredibly simple to print and the gripping mechanism is equally simple: By circling the belt around the standoffs, teeth inward, the belt grips itself by interlacing its own teeth like a zipper. This is probably the best choice in terms of printability and simplicity.
{% endcapture %}
{% include docs-step.html
  heading="#### Belt Clip Style 1"
  image="/assets/images/docs/stages/stage-3/belt-clip-1.png"
  content=belts1
%}

{% capture belts2 %}
This is a two-part clip that has more intricate details to print, so make sure to use a small enough nozzle and/or thin layers. While also a clever design, it does look like the wings on the outer clip housing run the risk of spreading under enough tension and allowing the belt to slip.
{% endcapture %}
{% include docs-step.html
  heading="#### Belt Clip Style 2"
  image="/assets/images/docs/stages/stage-3/belt-clip-2.png"
  content=belts2
%}

{% capture eva %}
**Usable Print Area:** 220 x 190 (30mm reduction on Y axis)

The EVA printhead is the standard Ratrig printhead. It has a large number of official addons including fan ducts, hotends, and extruders as well as [even more](https://www.printables.com/search/models?q=tag:eva3) parts created by the community. The main downside of this printhead is that its size causes about 10mm more lost print space on the Y axis than the Vz.

The official EVA v3 design only required three parts to be modified in order to work on the Endorphin, so you can start by reading up on the official [CoreXY printhead](https://main.eva-3d.page/heat_insert/core/corexy) and downloading most of the parts from this page. Just substitute the following parts for the Endorphin versions in this table:

| Original Part            | Endorphin Part                                                                                   |
| :----------------------- | :----------------------------------------------------------------------------------------------- |
| back_core_xy_fi.stl      | [eva-back_endorphin.stl](/assets/stl/docs/stages/stage-3/eva-back_endorphin.stl)                 |
| core_xy_belt_grabber.stl | [eva-endorphin_belt_grabber.stl](/assets/stl/docs/stages/stage-3/eva-endorphin_belt_grabber.stl) |
| top_endstop_mgn12c_fi    | [eva-eva-mgn9h.stl](/assets/stl/docs/stages/stage-3/eva-mgn9h.stl)                               |

You also don't need to print `face_belt_grabber.stl` because the Endorphin doesn't have a belt that attaches to the front of the EVA in the same way that a CoreXY does.

After you've printed the core printhead, you can choose the fan duct, hotend, and extruder that suits you. If you don't see your preferred parts on the official site, make sure to check sites like [printables](https://www.printables.com/search/models?q=tag:eva3) for what you need.

Credit for `eva-mgn9h.stl` goes to [@andbou_260448](https://www.printables.com/model/209376-eva-30-heat-set-mgn-9h-top-endstop)

{% endcapture %}
{% include docs-step.html
  heading="## EVA"
  image="/assets/images/docs/stages/stage-3/eva.png"
  content=eva
%}

{% capture evabelts %}
{% endcapture %}
{% include docs-step.html
  heading="### Belt Assembly"
  video="/assets/vids/docs/stages/stage-3/assembly-endorphin-belts.mp4"
  content=evabelts
%}

---

[← Back](/docs/stages/stage-2){: .btn .btn-outline .mr-4 .fs-5 } [Next →](/docs/firmware){: .btn .btn-outline .fs-5 }